|Systematic (IUPAC) name|
5'-Inosinic acid, homopolymer, complex with 5'-cytidylic acid polymer with 5'-uridylic acid (1:1)
Rintatolimod, sold under the tradename Ampligen, is a medication intended for treatment of chronic fatigue syndrome. However, there is only low-quality evidence that it can improve the people's ability to exercise.
Although Ampligen was cleared for use in Canada in 1997, and obtained orphan drug status for treatment of CFS in the European Union in 2000, it is so far without FDA approval and therefore classed as experimental in the United States. In 2007 it filed a New Drug Application (NDA) with the U.S. Food and Drug Administration (FDA) to market and sell rintatolimod for the treatment of CFS, but this was rejected in December 2009 because the FDA concluded that the two RCTs "did not provide credible evidence of efficacy" and "because of clinical, statistical, clinical pharmacology, nonclinical, product quality, and facilities inspection deficiencies." The FDA requested Hemispherx conduct at least one additional controlled trial to demonstrate efficacy in treating CFS. In August 2012 Hemispherx submitted further analyses of the original clinical trial data, although did not submit additional trials for review. Four months later a committee of the FDA voted 8-5 against approval for rintatolimod, again citing insufficient data.
Chronic fatigue syndrome
An independent review of rintatolimod clinical trials in chronic fatigue syndrome was published in the December 2006 issue of the Journal of Clinical Virology. It concluded that Ampligen has been "generally well tolerated", with a "low incidence of clinical toxicity", particularly when compared to the toxicity of the diseases it is used to treat. "No serious safety issues have resulted from the administration of ~75,000 doses IV (most commonly 400 mg) twice weekly for up to one year periods or greater. Animal toxicity studies support this observation in humans with primates demonstrating the greatest margin of safety." A mild flushing reaction has occurred in about 15% of patients, and more rarely reported side effects include chills, fever, malaise, leukopenia, neutropenia and leukocytosis. Some of these side effects may be attributed to a temporary Herxheimer reaction in response to pathogen die off. According to Hemispherx and patient testimonials, side-effects when they occur usually subside within three to four months or less.
Mechanism of action
A primary way rintatolimod acts is by protecting and stimulating the innate immune system, also called the nonspecific immune system and the first line of defense. According to a study published in the Journal of Immunology and reflected in a press release by Hemispherx, Rintatolimod protects and stimulates the innate immune system by binding to Toll-like receptors 3 (TLR-3), and activating the TLR-3 receptors for broad-spectrum immune response. TLR-3 receptors are located on cell surfaces. They are part of a family of "pattern recognition" receptors that detect pathogens immediately, even those the body has not yet encountered, long before adaptive immunity can intervene against foreign invaders. These receptors are critical to the first line of immunological defense against a broad range of pathogens, including otherwise lethal viruses and various forms of cancer. When, for example, double-stranded RNA molecules from an RNA viral infection bind to TLR-3 receptors the virus in this way inactivates the innate immune system, rendering it unable to signal the rest of the body's defenses. When rintatolimod binds to TLR-3 receptors the virus cannot do so and the body is able to marshal its defenses and launch an assault on the virus.
The mechanism of rintatolimod in relation to CFS is not certain but is thought to include the RNase L enzyme. Rintatolimod is a dsRNA, and when TLR-3 senses a dsRNA it is thought to relay a message to cells to produce interferons (IFNs). IFNs are a group of signaling molecules released by cells in response to the presence of pathogen viruses or bacteria. These signaling molecules activate (among other things) the protective defenses of the immune system that eradicate pathogens. One such defense mechanism thought to be activated by rintatolimod is the production of enzyme RNase L. This enzyme degrades pathogenic RNA both viral and cellular. Degradation of RNA prevents viral and cell replication, and destruction of all RNA within a virus or cell is the last stand before apoptosis or death. Accumulation of an inactive form of RNase L may be associated with CFS.
Rintatolimod development builds on a 1960s synthesis by Merck & Co., a double-stranded RNA compound of inosinic and cytidylic acid residues (poly I:poly C or poly I:C). Poly I:C inhibited tumor growth by inducing interferon production but was too toxic to use. In the mid-1970s, William A. Carter, a post-doctoral researcher at Johns Hopkins University, modified the dsRNA molecule by adding uridylic acid molecules at specific interval along the RNA chain. The new compound, called Ampligen (for AMPLIfied GENetic activity) stimulated interferon production like poly I:C, but was far kinder to the rest of the body. It is also known as "poly I:poly C12U".
Dr. Carter founded a company based upon the compound and licensed it from Johns Hopkins. By the late 1980s, Carter and his company, HEM Research, Inc., were pursuing human therapeutic uses for rintatolimod, as well as non-therapeutic uses, such as diagnostic testing for HIV and protecting plants from pathogens.
Rintatolimod was tested in clinical trials in United States of America beginning in 1988, after DuPont invested $30 million in Hemispherx. Initial success in a small trial for AIDS treatment was followed by difficulties in persuading the FDA to permit large scale trials. By 1991, it was thought that the chance of approval for a large trial being conducted in the USA had gone. Hemispherx then began to move clinical trials to Canada and Belgium.
In Belgium, rintatolimod has been available for use since the drug's trial beginning in May 1996. It has also been available under Canada's Emergency Drug Release Program for both chronic fatigue syndrome (CFS) and HIV treatment since 1996, with marketing rights controlled by Biovail Corporation International. An agreement between the Spanish company Esteve and Hemispherx in 2002 gave Esteve the rights to perform clinical trials at their own cost in Spain, Portugal, and Andorra. Bioclones (PTY) Ltd, a UK based company, was granted the exclusive marketing rights to rintatolimod in the United Kingdom, Ireland, and several countries in the Southern Hemisphere. The marketing agreement with Bioclones was terminated in 2005. Over its developmental history rintatolimod has received various designations including "orphan drug product" and "emergency compassionate cost recovery sales authorization," both from the FDA, and "promising" clinical outcome recognition based on the evaluation of certain summary clinical reports (AHRQ, Agency Health Research Quality).
According to the US National Academy of Sciences Institute of Medicine, "Chronic Fatigue Syndrome is a disease characterized by profound fatigue, cognitive dysfunction, sleep abnormalities, autonomic manifestations, pain, and other symptoms that are made worse by exertion of any sort. CFS can severely impair patients’ ability to conduct their normal lives." In October 2007 Hemispherx BioPharma submitted their first New Drug Application (NDA) to the FDA for rintatolimod to treat CFS. In December 2007 the agency deemed the application incomplete, citing deficiencies including lack of dose ranging, statistical analysis plans inconsistent with protocols, database discrepancies, and lack of clinical pharmacology and carcinogenicity data. In early 2009 Hemispherx again submitted rintatolimod for FDA approval for CFS treatment. The FDA scheduled their decision for May 25th of that year and twice postponed. The company received a Complete Response Letter from the agency on rintatolimod's NDA in December 2009 requesting further data.
In 2007, and again during the 2009 swine flu outbreak, William Carter said that rintatolimod could also be used as an H1N1 flu vaccine booster, citing in vitro studies with Ampligen and neuraminidase inhibitors oseltamivir and zanamivir (brand names Tamiflu and Relenza).
Hemispherx Biopharma continues to work with the FDA on rintatolimod approval for CFS treatment. On December 20, 2012 an FDA Advisory Committee voted in favor of rintatolimod's safety for commercial use (vote 8 to 5), but not in favor of its efficacy (4 to 9). The Complete Response Letter asked for more study data prior to rintatolimod approval. Recently, on January 12, 2015, the company released new in vitro study findings showing that low natural killer cell function associates with greater CFS disease symptom severity, and that rintatolimod treatment increases average NK cell activity over 100%. The new study report, "Low Natural Killer (NK) Activity Observed Across the Chronic Fatigue Syndrome (CFS) Disease Spectrum," has been submitted as a scientific paper for peer-review and publication. In addition to the new study findings the paper summarizes 6 supportive publications of results with more than 150 CFS patients correlating increased debility of CFS and low NK cell activity. Clinical testing is currently underway to determine whether NK cell activity augmentation by rintatolimod in vivo associates with lessened CFS disease severity and increased physical endurance and performance measures.
Twice, in 1998 and 2000, Hemispherx received notices of violation from the FDA for promoting rintatolimod as safe and effective before FDA approval, in violation of the Federal Food, Drug, and Cosmetic Act.
Also in the late 1900s, Manuel Asensio, a notorious short seller and former investment banker since expelled from the securities industry, reported on Hemispherx, saying the company was overvalued. He criticized Hemispherx and its rintatolimod results, alleging a variety of misdemeanors including accusations of refusing to supply rintatolimod after clinical trials have ended, and issuing misleading results to widen markets for rintatolimod.
In 1998, Hemispherx Biopharma filed a complaint against Asensio and his company, alleging defamation, conspiracy and interference with its business relations through a short-selling plot. After a jury rejected the defamation claims against Asensio, a mistrial was declared.
The following year, on November 2, 1999, Mary Schweitzer, a chronic fatigue syndrome patient who had been treated with rintatolimod, raised the question of why Ampligen has never been fast-tracked by the US public health authorities at the Chronic Fatigue Syndrome Co-ordinating Committee of the U.S. Department of Health and Human Services. Grassroots activism for FDA approval of Ampligen grew and continues. Current efforts in 2015 to spur FDA approval of Ampligen include petitions, appeal for congressional hearing, and popular social media group organizing.
Digital stock advisory The Street journalist, Adam Feuerstein, has published articles harshly critical of Hemispherx BioPharma, Inc., for over half a decade. In June 2009, Mr. Feuerstein alleged the company was "seeking to divert investors' attention away from the delayed approval of Ampligen as a treatment for chronic fatigue syndrome" by issuing three press releases in seven days about research from 2007 into possible applications for Ampligen as a flu vaccine booster, in which Hemispherx stated that Ampligen could be used against the H1N1 swine flu. The Street article also alleged the press releases were misleading because they implied the research had been done in 2009. When Hemispherx offered Ampligen as a potential H1N1 vaccine or vaccine booster the U.S. government turned them down and Mr. Feuerstein wrote, "Hemispherx Biopharma has been shut out of the U.S. government's efforts to stockpile vaccine against the H1N1 flu." Mr. Feuerstein's subsequent articles on Hemispherx BioPharma for The Street continue to run in similar vein.
Rintatolimod has been studied in people as far back as 2004. In early 2015 the AMP 511 open-label study of rintatolimod in CFS is still recruiting participants. Open-label studies are typically used when the controlled trial has ended and treatment is continued so that the subjects and the controls may continue to receive the investigational drug until marketing approval is obtained. Hemispherx management had missed several target deadlines for new drug application (NDA) filing in the past, including the end of 2005, the third quarter of 2006, and the first quarter of the year 2007. In October 2007, the US Food and Drug Administration (FDA) Ampligen NDA was filed. In December 2009 the FDA issued a CRL refusing Hemispherx's new drug application for rintatolimod's treatment of CFS. The FDA concluded that the two RCTs "did not provide credible evidence of efficacy." The agency recommended a minimum of one additional six-month 300 patient study, and rodent carcinogenicity studies.
Rintatolimod is taken intravenously. It is generally administered twice weekly for periods of one year or longer. Two toxicology studies are completed that establish the safety of intranasal and intramucosal methods of Ampligen administration, and Hemispherx has been researching their patented oral versions using nucleic acid technology related to rintatolimod.
- Smith, ME; Haney, E; McDonagh, M; Pappas, M; Daeges, M; Wasson, N; Fu, R; Nelson, HD (16 June 2015). "Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review for a National Institutes of Health Pathways to Prevention Workshop.". Annals of internal medicine 162 (12): 841–50. doi:10.7326/M15-0114. PMID 26075755.
- Official website
- Hemispherx Biopharma Files New Drug Application for Ampligen as Treatment of Chronic Fatigue Syndrome NDA of investigational drug includes four well-controlled trials, more than 1,200 trial subjects and 90,000 doses Cite error: Invalid
<ref>tag; name "Hemispherx" defined multiple times with different content (see the help page).
- George, John (December 3, 2009). "FDA rejects Hemispherx's chronic fatigue drug Ampligen". Philadelphia Business Journal. Retrieved 2010-02-12.
- Drug Development for Myalgic Encephalomyelitis and Chronic Fatigue Syndrome (ME and CFS): Questions and Answers - Food and Drug Administration, 5 February 2013
- Alibek K, Liu G. (May 2006). "Biodefense shield and avian influenza". Letter. Emerg Infect Dis. Retrieved 2007-12-14.
- "Hemispherx Presents Evidence of Ampligen Synergies with Existing Antivirals at International Avian Influenza Conference". BUSINESS WIRE. 2007-06-04. Retrieved 2008-04-26.
- Mitchell, W. (December 2006). "Review of Ampligen clinical trials in Chronic Fatigue Syndrome". Journal of Clinical Virology. 37, supp. 1: S113. doi:10.1016/S1386-6532(06)70079-8. Retrieved 2007-02-26.
- "Ampligen: Adrienne Dellwo (Updated 2014)"
- "FDA Letter Section: Abstracts of Patient Session on Ampligen (1998)"
- Gowen BB, Wong MH, Jung KH, Sanders AB, Mitchell WM, Alexopoulou L, Flavell RA, Sidwell RW (April 2007). "TLR3 is essential for the induction of protective immunity against Punta Toro Virus infection by the double-stranded RNA (dsRNA), poly(I:C12U), but not Poly(I:C): differential recognition of synthetic dsRNA molecules". J. Immunol. 178 (8): 5200–8. doi:10.4049/jimmunol.178.8.5200. PMID 17404303.
- Suhadolnik RJ, Reichenbach NL, Hitzges P, Adelson ME, Peterson DL, Cheney P, Salvato P, Thompson C, Loveless M, Müller WE (1994). "Changes in the 2-5A synthetase/RNase L antiviral pathway in a controlled clinical trial with poly(I)-poly(C12U) in chronic fatigue syndrome". In Vivo (Athens, Greece) 8 (4): 599–604. PMID 7893988.
- "RNase L: Its Biological Roles and Regulation" (2006)
- Nijs J, De Meirleir K (2005). "Impairments of the 2-5A synthetase/RNase L pathway in chronic fatigue syndrome". In Vivo 19 (6): 1013–21. PMID 16277015.
- Kitei, Mindy. A History of Ampligen: The AIDS Drug No One Can Have." Philadelphia Magazine. October 1994. Retrieved on February 25, 2007.
- "Business Description: HEM Research, Inc." 1986. Retrieved on February 25, 2007.
- Johnson, H (1996). Osler's Web: Inside the Labyrinth of the Chronic Fatigue Syndrome Epidemic. Crown Publishing Group. pp. 647–9. ISBN 051770353X.
- Melnyk, Eugene; Howling, Kenneth G. "Biovail Acquires Ampligen Marketing Rights for Canada; New Treatment for Chronic Fatigue Syndrome." Biovail Corporation International|Biovail. February 11, 2000. Retrieved on February 25, 2007.
- "SEC Filing (Form S-3): Hemispherx Biopharma, Inc.." January 14, 2003. Retrieved on February 25, 2007.
- "Mismatched Double-Stranded RNA: Ampligen, Oragen, Polyi:Polyc12u." Drugs in R&D. February 1, 2002. Retrieved on February 26, 2007.
- "Item 3. Legal Proceedings." Edgar-Online retrieval February 2, 2015
- "Securities and Exchange Commission
- "Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness" February 10, 2015
- http://www.fda.gov/Drugs/NewsEvents/ucm337759.htm ["FDA Drugs: News & Events"]Last Updated 02/05/2013: Retrieved February 21, 2015
- "Hemispherx Biopharma,HEB - Losing Ground" June 5, 2009
- "Hemispherx says FDA decision on Ampligen months away" John George, Philadelphia Business Journal, July 22, 2009
- "Hemispherx gets FDA Complete Response Letter on Ampligen NDA" Dec 1, 2009
- "Ampligen Synergies with Existing Avian Flu Antivirals" (June 4, 2007) Retrieved February 21, 2015
- "US National Academy of Sciences Institute of Medicine Reframes Chronic Fatigue Syndrome (CFS)"
- http://www.fda.gov/Drugs/NewsEvents/ucm337759.htm ["FDA Drugs: News & Events"] Last Updated 02/05/2013: Retrieved February 21, 2015]
- "Hemispherx Press Release" (February 23, 2015)
- Notice of Violation - FDA, 7 July 2000,
- Notice of Violation - FDA, 15 Oct 1998
- Asensio & Company: Hemispherx Analyst Makes False Ampligen HIV Efficacy Claims Despite Failed Test and FDA Violation Notice Archived August 28, 2006 at the Wayback Machine
- Ampligen: Excerpts from Osler's Web Archived February 4, 2007 at the Wayback Machine
- Securities and Exchange Commission
- "My History with ME/CFS:Mary M. Schweitzer, Ph.D."
- "Congressional Hearing:Ampligen FDA Roadblocks"
- "Ampligen Facebook Page"
- "Hunger Strike for Ampligen"
- "Why No Antivirals & Ampligen?" (2011) YouTube Video
- "Ampligen patient speaking to an FDA representative" (2013) YouTube Video
- "Adam Feuerstein: Profile"
- "Hemispherx Builds False Hope on Old Data," Adam Feuerstein, The Street, June 5, 2009
- "Hemispherx Not Among 4 to Get H1N1 Flu Contracts" Adam Feuerstein, The Street, July 14, 2009
- Edgar pro
- ClinicalTrials.gov: Study of Ampligen in Chronic Fatigue Syndrome
- fda.gov: Guidance for Institutional Review Boards and Clinical Investigators
- Edgar pro
- "Ampligen". Hemispherx Biopharma. Retrieved 2008-04-26.
- "Product Candidates Under Development" (2015)
- Ampligen Improves Function of NK Cells Obtained from CFS Patients
- http://sec.gov/Archives/edgar/data/946644/000114420407023929/v074337_10q.htm, p. 20
- "Hemispherx Biopharma Receives New Patents for Oral Broad-Spectrum Immune Activators (2003)" Retrieved February 8, 2015
- "Mismatched double-stranded RNA: polyI:polyC12U (Abstract 2004)" PubMed retrieval February 8, 2015